Identify each example on the diagram as a carbon source or a carbon sink.

Plants and animals RE a carbon source during respiration. they take in Oxygen and give out Carbon (IV) oxide as a by product.  Combustion of fossil fuels is also source of carbon (IV) Oxide.

Formation of fossils from dead plants and animals is a carbon sink. photosynthesis is also a carbon sink as plants take in carbon (IV) Oxide that is used to make food.

answer; /// i do believe that the correct answer is (c)nuclear bond

i think the answer is terrae but not 100 percent sure. ▓▬▬ §